How do high pressures favour the formation of ammonia in dinitrogen reduction?

2 Answers
Apr 20, 2016

Answer:

Haber process is used to make ammonia

Explanation:

The Haber process is the process in which ammonia is made by combining nitrogen and hydrogen with the use of an iron catalyst, high temperature and 200 atmospheric pressure.

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Pressure is used so that the equilibrium shifts to the side with fewer moles of gas, the ammonia.

A high temperature is used so that the rate of reactions is increased but the yield of ammonia is decreased. It is a reversible reaction so some of it becomes ammonia but it reverts back to nitrogen and hydrogen.

The nitrogen and hydrogen that have not reacted are reused.

Apr 20, 2016

Answer:

#N_2(g) + 3H_2(g) rarr 2NH_3(g)# is the stoichiometric reaction.

Explanation:

High pressures favour the forward process, and typically the process is conducted under pressures of some #200# #atm#.

Since the reaction is exothermic, it is tempting to speculate that lower temperatures would favour the forward reaction. Unfortunately, at lower temperatures the rate of reaction is unacceptably low. A temperature of #400-500# #""^@C# provides acceptable rates, and since the ammonia gas is condensable the reactant gases can be recycled, and returned to the equilibrium.

Note that a solid catalyst (a closely guarded secret) would be present in the reaction, to allow the reactants to come to equilibrium quickly.